Thursday, December 02, 2010

Quieter start to December..

After a snowy and stormy second half of November, December will start off on a quieter note over southern MB along with below normal temperatures. An arctic ridge of high pressure will dominate the weather pattern over the Prairies through the upcoming weekend with generally sunny skies, light winds and seasonably cold temperatures. A system passing to the south of the border will brush SW Manitoba overnight into Friday with some snow, but the bulk of that system will track into North Dakota Friday. Dry weather is expected into the beginning of next week - which will come as a relief to overworked snow crews who have been kept busy by frequent snowfalls over the past 2 weeks over southern MB. In Winnipeg, 55 cm of snow has fallen between November 18th and 30th, resulting in the heaviest November snowfall in the city since 1996 (62.8 cm) (see Nov 2010 monthly summary)

A bit off topic...but with that system giving snow to cntrl-srn ND into MN....getting reports as of 5 pm of 6-8 inches in a band from north of Bismarck to just south of Jamestown then to the Lake Traverse area.... convective bands reported with whiteout conditions in hvy snow expected 10-12 inches in narrow axis down that way.

Winnipeg is within 11 mm of setting an all time wettest year on record. As of yesterday, the airport had registered 712.5 mm of total precipitation this year (combined rain and melted snow) making it the 4th wettest year since Winnipeg records began in 1872. The wettest year on record is currently 1962 with 723.6 mm. What makes this year's stats more impressive is that we were very dry through April, meaning the majority of the precipitation this year has fallen in the past 7 months.

And yes.. very impressive warmth over Baffin. Today was Iqaluit's 6th record high in the past 7 days. A blocking ridge over Greenland is pushing storm systems to the west of the island, allowing mild moist Atlantic air to flood over Baffin Island. Very strange to be seeing bare ground in Kimmirut while we wade through deep snow. But the warmth has been happening all year up north. Parts of the the Canadian Arctic have recorded their warmest winter, spring and summer this year, and most likely its warmest fall as well. That is what has contributed most to this year likely being the warmest year on record in Canada.

As daniel noted, Winnipeg has hit -40C several times in December, including our all time low of a ridiculous -47.8C on Dec 24 1879 (the HIGH that day was -39.4C!!)

That being said, it's been over 75 years since Winnipeg has hit -40C in December, the last time being Dec 28, 1933. Most of Winnipeg's -40C December readings were in the 1800s. So, it's become a lot rarer than it used to be! However, we still can hit the elusive -40C mark during winter.. the last time being Feb 5 2007 when the airport hit -41.7C.

Speaking of -40, I came across an interesting website/blog from Yakutsk, Russia.. a city of 200,000 people in Siberia considered the coldest city in the world. The site is a fascinating account of life in Siberia which routinely gets down to -40 to -50 C in the winter. Lots of good entires, video clips, and some beautiful photographs from the "Pole of Cold" region. See http://eyakutia.com/ or click on my name for link..

How times have changed!!A year ago at this time we lamented a lack of snow and finally had some cold weather after one of the warmest and dryest Novembers. The Red River and Lake Winnipeg had just started to freeze.See this 2009 Dec 05 Snow Cover Map and this for Todays Snow Cover Map

Snowfall reports in excess of 70cm in Southern Ontario from lake-effect snow. EC is talking about total snowfall amounts of 1m (100cm) or more by the time the snow ends. That is like having our entire winter's snow in a few days! Sure would be interesting to experience something like that.

I think we talk about weather advisories like this every winter, but it never gets old:

A COLD AIR MASS WILL IMPACT SOUTH FLORIDA OVER THE NEXT FEW DAYS.LOW TEMPERATURES TONIGHT WILL RANGE FROM -4 TO +1 NEAR LAKE OKEECHOBEE WITH THE REST OF SOUTH FLORIDA between-1 and +4...EXCEPT AROUND +4 OVER THE SOUTHEAST PORTION OF SOUTHFLORIDA. THESE COLD TEMPERATURES COMBINED WITH NORTHWEST WINDS OF8 TO 16 KMH WILL ALLOW FOR WIND CHILL READINGS TO FALL TO BETWEEN-4 AND +1...EXCEPT FOR METRO PALM BEACH WHERE THE WINDCHILL READINGS WILL BE NEAR -4 TOWARD SUNRISE TUESDAY.

Models showing clipper moving across southern MB basically along the TransCanada highway spreading snow over us Wednesday night into Thursday. Early consensus is for a general 5 cm or so across the Transcanada corridor including Winnipeg, and 10 cm further north over Dauphin into the central Interlake areas. A non-event compared to the major lake effect snow they're getting in southern Ontario, but for us, it will be our first accumulating snow event since the end of November.. Will post a new thread on this system shortly..

Rob Why is the lake effect snow in SW Ontario a heavy Wet snow while we get fluff here?

You can drive from Windsor east along Lake Erie north shore in late November, or early December in balmy +16C sunshine. Within the first 100Km, snow squalls can dump that meter of snow in less than 2 hours all the way up to London and strangle the 401. A heavy wet snow I might add.

Their lake effect events are sometimes closer to the 0C mark, so the snow will be wetter and heavier than when it's colder (like here) However, lake effect snow is still a lot more fluffy than "normal" snow, even down there. Taking a look at some of the photos from there, you can see its a powdery snow (and lots of it!)